One paragraph in President Barack Obama’s initial speech on the Iran deal was superb, and, though he buried it near the end, it was and is the crucial paragraph—the one paragraph that may turn out to justify everything else in the speech. This was the paragraph in which Obama spoke directly to the Iranian people:Our differences are real, and the difficult history between our nations cannot be ignored. But it is possible to change. The path of violence and rigid ideology, a foreign policy based on threats to attack your neighbors or eradicate Israel—that’s a dead end. A different path, one of tolerance and peaceful resolution of conflict, leads to more integration into the global economy, more engagement with the international community, and the ability of the Iranian people to prosper and thrive.In case anyone failed to pay attention, he pretty much repeated that one paragraph in his interview later in the day with Thomas L. Friedman, with a few words about how the Iranians don’t have to “denigrate Israel or threaten Israel,” and so forth—though once again the argument came at the end, as if it were an afterthought.That one paragraph is crucial because, if a change among the Iranians is not, in fact, possible, then Obama’s critics are right. The deal will turn out to be a disaster because, in the short run, it will strengthen the Islamic Republic conventionally and, in the long run, will strengthen the Islamic Republic unconventionally—and, all the while, the Islamic Republic will go on treading the dead-end path of violence and rigid ideology and the dream of eradicating demonic enemies. It is hard to imagine how, under those circumstances, the deal will reduce the chances of war. On the contrary, Iran’s endangered neighbors will contemplate their own prospective eradication and will certainly notice that time is against them, and they would be foolish not to act.And if the deal turns out to be a good deal? This could be the case on one ground only: if the deal promotes the kind of Iranian interaction with America and the world that, as the years go by, will erode the appeal of “rigid ideology.” And the deal will turn out to be good—better than good, magnificent—if it buys sufficient time to allow the erosion to take place and the change in thinking to occur. Everything depends on this one point. So, the deal is a wager on Iranian evolution, and Obama knows this to be the case, even if he says otherwise—which is why he keeps presenting us with afterthoughts.Shouldn’t this reality suggest a policy intended to promote such an evolution? I mean an active policy, and not just hoping for the best. I can appreciate why no one is in a rush to discuss such a policy. The United States has not enjoyed a lot of success in bringing about ideological transformations in the larger Middle East. George W. Bush’s “Freedom Agenda” set out to achieve such a thing; and Obama’s support for the Arab Spring set out to achieve the same thing in a different fashion; and, in regard to Iran, Obama tried in still another way by squeezing with sanctions. (Though it was odd that, back in 2009, when the dissident Green Movement was in the streets, he declined to try, and our best friends were left unsupported.) But his nuclear negotiation offers a new occasion.What would a policy designed to bring about a change in Iranian thinking look like? I think one part of it would look like Obama’s afterthought paragraph in yesterday’s speech—the paragraph I have quoted. He spoke about ideology, and he singled out the hatred of Israel, and his arguments were good. We need a policy that will make the same arguments on a grand scale, not in the form of ridiculous propaganda (which was a Bush instinct) but in a serious spirit, maybe not even as a government policy. If the nuclear deal is going to bring great numbers of Iranians in contact with the rest of the world, we liberals and democrats ought to be able to address the Iranians directly, regardless of our own government or theirs. Sixty and 70 years ago the liberal journalists and intellectuals in the old Committee for Cultural Freedom and the Congress for Cultural Freedom used to put up serious arguments against the totalitarian currents of the day, and there is no reason why this couldn’t be done in our own day. If Obama’s nuclear deal turns out to be a good deal—it had better turn out to be a good deal—the success will derive precisely from that sort of effort: a campaign of persuasion. An ideological de-toxification campaign. A debate over Islamism, and over maniacal hatred of the Jews. This has to be our future.***Like this article? Sign up for our Daily Digest to get Tablet Magazine’s new content in your inbox each morning.